Illustrated herein in embodiments are toner processes, and more specifically, emulsion aggregation and coalescence processes. More specifically, disclosed in embodiments are methods for the preparation of toner compositions by a chemical process, such as emulsion aggregation, wherein non-crosslinked latex particles, such as latexes containing non-crosslinked vinyl polymeric particles, are aggregated with a polyester, such as a crystalline polyester (CPE), optional crosslinked latex particles, such as latexes containing crosslinked vinyl polymeric particles, a wax and colorants, in the presence of a coagulant like a polymetal halide, followed by adding a latex containing further resin particles comprising a charge control agent, such as in the form of a copolymer containing charge control agent recurring units to form a shell around aggregated particles, and thereafter stabilizing the aggregates and coalescing or fusing the aggregates by heating the mixture above the resin Tg to provide toner size particles.
A number of advantages are associated with the toner obtained by the processes illustrated herein. For example, conventional processes that incorporate a crystalline polyester into the toner particles, provide toner particles that generally exhibit reduced charging properties in high temperature and high humidity environments and in low temperature and low humidity environments. The terms “high temperature” as used herein refers to a temperature of about 80° F. or about 28° C., and “low temperature” as used herein refers to a temperature of about 50° F. or about 10° C. Likewise, the terms “high humidity” as used herein refers to a relative humidity of about 80-85%, and “low humidity” as used herein refers to a relative humidity of about 10-15%. However, the reduced charging properties in such environments can be countered by incorporating a charge control agent into the toner particles. Incorporating a charge control agent, such as in the form of a copolymer containing charge control agent recurring units, into a shell on the toner particles can counter the reduced charging, while still allowing desirable relative humidity sensitivity effect.